Eukaryotic Transcription and Translation

Question 1

RNA pmrs which transcribes large ribosomal RNAs (nucleolus)

Answer 1

Pol 1 (2nd step)

Question 2

pmrs that transcribes mRNA

Answer 2

Pol 2 (3rd step)

Question 3

pmrs that Transcribes most small RNAs, tRNAs and RNAs involved in processing primary RNA transcripts

Answer 3

Pol 3 (1st step)

Question 4

Guanyltransferase aids in addition of 5’ methyl caps to transcript. What is the purpose of this?

Answer 4

cap used for ribosome assembly during translation initiation

Question 5

This signal serves as recognition site for cleavage factors and poly A pmrs

Answer 5

AAUAAA

Question 6

These DNA sites bind proteins that stabilize RNA polymerase at the promoter…

Answer 6

TATA or Goldberg-Hodness box

“caat box”

Question 7

: interact with the promoter to facilitate binding of RNA polymerase II

Answer 7

General (basal) transcription factors

Question 8

(TFIID) is capable of interacting with several factors that are required for the assembly of a productive transcription complex…

Answer 8

TATA binding protein

Question 9

can influence the formation of a productive transcription complex…

Answer 9

Specific Transcription Factors (STFs)

Question 10

STFs may bind at some distance from the promoter…_________ sequences (Fig.

Answer 10

enhancer

Question 11

When basal factor and ______ are bound to DNA, rate of transcription increases

Answer 11

activator

Question 12

part of primary transcript which is removed

Answer 12

intron

Question 13

used to remove introns

Answer 13

SNRPS and the spliceosomes

Question 14

this forms after the OH border of the intron is clipped

Answer 14

lariat formation

Question 15

the idea that exon/intron organization may facilitate evolution of new genes…

Answer 15

Exon shuffling hypothesis

Question 16

highly conserved proteins that are intimately associated with the DNA in chromatin

small in size
carry a large number of basic residues
complexed into a particle termed a small in size
carry a large number of basic residues
complexed into a particle termed a _____

Answer 16

histones; nucleosome

Question 17

In calf thymus DNA, as lysine content decreases, what happens to MW?

Answer 17

it also decreases (arg increases)

Question 18

______ required for formation of 30 nm fiber…

Answer 18

H1

Question 19

beads on a string’ in different stages of condensation…

Answer 19

nucleosomes

Question 20

Higher order folding:

loops of DNA are believed to associate with a _______

Answer 20

protein scaffold

Question 21

associated with scaffold attachment regions

Answer 21

Topoisomerase 2

Question 22

T/F: RNA polymerase appears to displace histone octamers during transcription

Answer 22

true

Question 23

It is possible to distinguish “active” from “inactive” chromatin by susceptibility to enzyme digestion
In _____ chromatin, beta globin gene is not expressed- beta globin gene DNA LESS susceptible to DNAse digestion
In ______ chromatin, beta globin gene expressed- MORE susceptible to DNAse digestion.

Answer 23

liver

reticulocyte

Question 24

Displacement of histones by _______ allows access to promoter

Answer 24

remodeling proteins

Question 25

removal of histones causes ______

Answer 25

DNAse hypersensitive sites

Question 26

For the E. coli lab operon, a separate gene locus encodes ____, which binds to the DNA near the lac promoter, interfering with RNA pmrs transcription

Answer 26

repressor protein

Question 27

glucose + galactose =

Answer 27

lactose

Question 28

____ gene synthesizes a protein that represses operon transcription

Answer 28

I gene (product is negative regulator)

Question 29

in the presence of lactose, repressor binds to _____, changes shape and loses affinity for operator

Answer 29

sugar

Question 30

In absence of lactose, repressor protein binds to lac DNA at a specific control region, the operator. This interaction does what?

Answer 30

prevents transcription

Question 31

B-Galactosidase fxt

Answer 31

cleaves lactose to monosaccharides

Question 32

Permease fxt

Answer 32

allows lactose to enter cell

Question 33

Transacetylase fxt

Answer 33

unclear

Question 34

In presence of lactose, Repressor dissociates from the operator site, allowing RNA polymerase to transcribe the operon… enzyme synthesis is induced by ?

Answer 34

lactose

Question 35

“Gratuitous” Inducer…will induce operon, but not be metabolized by beta galactosidase What molecule?

Answer 35

IPTG

Question 36

T/F: In absence of inducer (lactose analog for induction), repressor occupies operator, preventing transcription (binds to DNA)

Answer 36

True

Question 37

In presence of inducer (lactose analog) _____ is transcribed, due to interaction of inducer with repressor (repressor no longer binds to DNA)

Answer 37

promoter

Question 38

mechanism of induction was established by ______

Answer 38

mutational analysis

Question 39

Operon is transcribed in absence of inducer...constitutive expression in the absence of lactose- always on…. When does this happen?

Answer 39

When there is no active repressor protein (I- mutation)

Question 40

Oc mutation (in operator region) shows _______ expression b/c Oc mutatnt can't bind repressor and will express downstream genes even in absence of inducer

Answer 40

constitutive expression

Question 41

Genetic Analysis of mutants in ______ permitted characterization of roles of operator and repressor

Answer 41

merodiploids

Question 42

I- has ______ phenotype relative to functional gene…I gene makes a diffusible product that acts in trans….

Answer 42

recessive

Question 43

Oc mutant can’t bind repressor and is ____ dominant: will always express even in absence of inducer, but only those genes to which it is ______ to the mutant operator will be expressed….

Answer 43

cis; physically linked

Question 44

____ acts in cis, consistent with it being a DNA binding site...

Answer 44

operator

Question 45

______ acts in trans, consistent with it being a diffusible substance (protein)

Answer 45

repressor

Question 46

T/F: I^s has a dominant phenotype; will occupy a wild type operator and not be removed by inducer

Answer 46

true

Question 47

T/F: In the presence of glucose, lac operon is not transcribed

Answer 47

true

Question 48

T/F: The ratio of ATP to cAMP in the cell is used to evaluate its metabolic status During high levels of ATP, cAMP levels are elevated

Answer 48

false: Under low levels of ATP, cAMP levels are elevated

Question 49

_____ is required as a positive activator of the lac operon...

Answer 49

cAMP

Question 50

T/F: cAMP is required for CAP (catabolite activator protein) to bind to DNA

Answer 50

true (positive control)

Question 51

When glucose is present, cAMP levels are ____

Answer 51

low, CAP can't bind..very little lac mRNA

Question 52

when no glucose is present, cAMP is ____

Answer 52

high; cAMP/CAP complex form, abundant lab mRNA

Question 53

T/F: I+ is always inducable, Is is always repressed, Is is dominant to I+

Answer 53

True

Question 54

_____ requires additional cofactor for stimulation of transcription

Answer 54

positive control

Question 55

repressor molecule impedes transcription is what type of control?

Answer 55

negative

Question 56

NRs characterized by two highly conserved regions:

Answer 56

C Domain: binds to DNA (DBD) E Domain: binds to signaling molecule (e.g. hormone ligand) (LBD) portions of C and D domains are also involved in dimer formation

Question 57

a large fam of TFs found in both vertebrates and invertebrates

Answer 57

nuclear receptor superfamily

Question 58

binding site for nuclear receptors

Answer 58

Hormone response element

Question 59

formation of _______ through recruitment of specialized transcription factors and/or chromatin modification

Answer 59

active transcription complex

Question 60

a fundamental measure of genetic variation are the ________ at any given locus

Answer 60

allele frequencies

Question 61

Factors that affect changes in allele frequency in populations over time are:

Answer 61

1recurrent mutation 2natural selection 3migration 4: random sampling effects

Question 62

for any given _____ , the observed values conform well to the expected values... but the species as a whole shows a wide variation in genotype frequencies...

Answer 62

subpopulation

Question 63

T/F: positive assortative mating for relatedness, or negative assortative mating for differences, can lead to changes in frequency of homozygosity

Answer 63

true

Question 64

in human populations (e.g. M/N blood group example) individuals will tend to mate within their own subgroup. This is called ?

Answer 64

endogamy

Question 65

What are the 5 conditions of HW equil?

Answer 65

``` mating is random (previously discussed) there is no selection there is no migration infinite population size no mutation ```

Question 66

random change in gene frequencies due to sampling effects

Answer 66

genetic drift

Question 67

change in gene pool due to immigration or emigration between populations

Answer 67

gene flow

Question 68

differential reproductive success favors some alleles over others Mutation: change in allele frequency due to net mutation

Answer 68

natural selection